Apparatus for calibrating flow meters and the like

Apparatus for use in measuring the flow rate of a gas, comprising:

• a container having means for introducing a gas into the interior of said container;
• piston means slidably mounted in said container and being moved by the gas introduced or removed from said container;
• encoder means for generating a signal representing each change in a predetermined unit of volume;
• coupling means responsive to movement of said piston means for activating said encoder means;
• sliding seal means for providing a gas-tight sliding seal between the interior of said container and said piston means;
• said sliding seal means comprising a liquid mercury seal;
• said container having a floor;
• and
• said floor sloping downwardly and inwardly from the interior wall toward a central location of said floor to collect any liquid mercury dripping from the region of said sliding seal at said central location.

Apparatus for use in measuring the flow rate of a gas, comprising:

• a container having means for introducing a gas into the interior of said container;
• piston means slidably mounted in said container and being moved by the gas introduced or removed from said container;
• encoder means for generating a signal representing each change in a predetermined unit of volume;
• coupling means responsive to movement of said piston means for activating said encoder means;
• said piston means being provided with an annular groove facing the interior surface of said container;
• and
• liquid mercury being provided in said groove and engaging the interior of said container to provide a gas-tight seal between said piston means and said container to prevent the escape of the gas being introduced into said container;
• a centrally located inlet opening being provided in the floor of said container;
• and
• a tube extending upwardly from said inlet opening and having an upper end arranged a spaced distance above the level of the floor surrounding said centrally located opening to prevent liquid mercury collected on said floor from entering into said tube and said inlet opening.

Apparatus for use in measuring the flow rate of a gas, comprising:

• a container having means for introducing a gas into the interior of said container;
• piston means slidably mounted in said container and being moved by the gas introduced or removed from said container;
• encoder means for generating a signal representing each change in a predetermined unit of volume;
• coupling means responsive to movement of said piston means for activating said encoder means;
• said piston means further including release valve means for releasing the gas within said container to the atmosphere when the pressure in said container reaches a predetermined magnitude.